This invention relates generally to eyeglass frames and more specifically to those frames which incorporate a laterally extending brow bar to which the individual lenses are directly connected. Such connection is generally either by screw members passing through the brow bar and then through spaced openings provided in the lens to which a retaining means such as a nut is secured to the opposite end of the screw members to maintain the parts in assembled relation, or the screw members are threaded studs fixedly secured to the brow bar and extending rearwardly therefrom. In either case a problem exists, particularly with highly curved lenses, such that when the above described connecting means is tightened, the curved center portion of the lens engages the brow bar. Accordingly, upon tightening one of the threaded studs, a pivotal movement is set up between that central portion of the lens that is in contact with the brow bar and the spaced securement positions or lens openings. This causes a rocking of the lens with respect to the brow bar when the studs are alternately tightened and may even prevent a secure engagement between the brow bar and the lens.
It is generally impractical to shape the inner face of the brow bar to match the particular curvature of the outer face of the lens since there are so many different possibilities of lens curvatures. Accordingly, brow bars are generally formed of straight construction although a slight curvature may exist to at least partially follow the natural contours of the average wearer's face. In order to solve the aforementioned problem, it has been suggested that a portion of the lens be cut away so as to provide a flat surface for receipt of the brow bar to thus prevent rocking of the lenses when mounted. Such construction is shown in U.S. Pat. No. 2,178,038 issued Oct. 31, 1939 (copy enclosed). Such solution, however, involves a rather expensive secondary operation, i.e. grinding of the lenses. Accordingly, it would be desirable to prevent the contact between the outer face of the lens and the inner face of the brow bar during mounting so as to eliminate such undesirable rocking action.
Accordingly, the principal object of the present invention is to provide a construction which enables lenses and particularly those exhibiting a highly curved configuration to be satisfactorily mounted to the brow bar portions of a frame so as to be disposed out of contact therewith, and at the same time so as to extend substantially straight down from the brow bar.
This and other objects of the present invention are accomplished by an eyeglass frame having a generally laterally extending brow bar and at least one lens having a convexly curved outer face. The lens is attached to the brow bar at two laterally spaced positions along the bar and adjacent the upper edge portion of the outer lens face. The lens is provided with an opening at spaced locations corresponding to the attachment positions and each opening includes an enlarged counterbore disposed into the outer lens at an angular relation thereto, and generally coaxial with the openings, the openings and counterbores extending substantially perpendicular to the rear plane of the lenses. The bar includes a pair of posts adapted to extend at least partially through each of the openings. A spacer bushing is held in position on the threaded posts such that the opposite end faces thereof are respectively engaged with the inner face of the brow bar and the counterbore of the lens such that the lens and brow bar are maintained out of contact with each other during both their mounting and final positioning. Such construction enables lenses, even those exhibiting highly convex faces, to be satisfactorily positioned and mounted on brow bars that are either straight or exhibit less curvature than the lens.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawing.